from __future__ import annotations

import logging
from dataclasses import dataclass

import requests

from app.ha.exceptions import (
    HaAuthError,
    HaHttpError,
    HaTimeoutError,
    HaUnexpectedPayloadError,
)

logger = logging.getLogger(__name__)


@dataclass(frozen=True)
class HaClientSettings:
    url: str
    token: str
    timeout_seconds: int = 10


class HaClient:
    def __init__(self, settings: HaClientSettings) -> None:
        self._settings = settings
        self._session = requests.Session()
        self._session.headers.update({
            "Authorization": f"Bearer {settings.token}",
            "Content-Type": "application/json",
        })

    def list_entities(self) -> list[dict[str, object]]:
        try:
            response = self._session.get(
                f"{self._settings.url}/api/states",
                timeout=self._settings.timeout_seconds,
            )
        except requests.Timeout as exc:
            raise HaTimeoutError("Zeitüberschreitung beim Zugriff auf Home Assistant.") from exc
        except requests.RequestException as exc:
            raise HaHttpError(
                getattr(getattr(exc, "response", None), "status_code", 502),
                "Netzwerkfehler beim Zugriff auf Home Assistant.",
            ) from exc

        if response.status_code in (401, 403):
            raise HaAuthError(
                response.status_code,
                "Authentifizierung bei Home Assistant fehlgeschlagen.",
            )

        try:
            response.raise_for_status()
        except requests.HTTPError as exc:
            raise HaHttpError(
                response.status_code,
                "Home Assistant meldet einen Fehler.",
            ) from exc

        try:
            payload = response.json()
        except ValueError as exc:
            raise HaUnexpectedPayloadError(
                "Antwort von Home Assistant ist kein gültiges JSON."
            ) from exc

        if not isinstance(payload, list):
            raise HaUnexpectedPayloadError(
                "Antwort von Home Assistant hat unerwartetes Format."
            )

        return payload